Adapting TPMA code

How do I adapt TPMA code? Example: 28 days readmissions - changing the days

Step 1: adapting the function in nhp_data

Step 2: turning the counts into rates

How fixed are TPMAs - what can we change and when?

Are they "sacred"? How do we approach amendments when there is a need to revise the definitions? What are the pitfalls of this? How do we clearly version control the TPMA definitions (in English and in code (Python/PySpark?)) ?